Radiation therapy is one of the main treatment methods for cancer. Machine learning can be used in all aspects of clinical practice in radiation therapy, including clinical decision support, automatic segmentation of target volumes, prediction of treatment efficacy and side effects. Despite the challenges of lacking structured data and poor interpretability of models, the application of machine learning in radiotherapy will become increasingly profound and extensive. This review contains three aspects: introduction of machine learning, the clinical application of machine learning in radiotherapy, challenges and solutions.

Asthma, often begins in childhood, can affect dental health. In return, dental treatment and dental anxiety can lead to an acute asthmatic attack. This article reviews the potential influence of asthma on dental treatment and dental medications and specifically describes the modes of dental conscious sedation in asthmatic patients.
Anesthesia, Dental ; methods ; Asthma ; etiology ; Dental Anxiety ; complications ; Humans

OBJECTIVETo evaluate the attention shift effect produced by a video-audio eyewear in pediatric dentistry.

METHODSTotally 40 children aged 4-7 years were equally randomized into fissure sealant group(group S) and caries filling group(group F). A self-control comparison method was used in each group: each child took two visits to finish the whole study, they received the dental treatment either with normal method(SC, FC) or with attention shift by wearing the video-audio eyewear (SI, FI) for each visit. The degree of pain, accomplishment of treatment, and co-operation were analyzed and compared.

RESULTSAll children were successfully managed in the whole course. The pain scores were not significantly different between SC group and SI group or between FC group and FI group (P0.05), while the Frankl scores were significantly different between SC group and SI group (P=0.04) and between FC group and FI group (P=0.03). Houpt scores were significantly different between SC group and SI group (P=0.04), but not between FC group and FI group (P=0.85). Most children (90% in group S) and (85% in group F) expressed the willingness to receive the video-audio eyewear if they were asked to do so again.

CONCLUSIONSThe video-audio eyewear provides satisfactory attention shift for children during dental treatment and increases their cooperation. However, it has little effect on pain relieving.

Objective　To find out if an unique blood mode-vasculogenic mimicry (VM) exist in prostate cancer and analyze its relationship with prognosis.　Methods　The age of the patients was 59 to 72 years,with a mean age of (66.7 ± 11.0) years.All had been confirmed as prostate cancer by biopsy.The level of serum PSA was 15.6 to 76.7 μg/L,with a mean level of (34.6 ± 1.7 ) μg/L.A histochemical and immunohistochemical dual staining method for PAS-CD31 and MMP-2 in 96 prostatic adenocarcinomas were conducted to explore if VM exist in prostate cancer,describe its morphology and distribution.The different expression of MMP-2 in VM positive and VM negative tissue were.The clinical data were collected and analyzed to explore the relationship between disease progression and VM.　Results　Among 96 cases,24 cases were found VM positive,the others were negative.The boundary membrane of VM was PAS positive,which was continuous or incontinuous. A positive correlation between VM density and high Gleason score were found.The tPSA were higher in the VM positive cases than that in VM negatives.The VM positive patients had poorer prognosis than that of the negatives.The MMP-2 expression was found correlated with VM positive (rs =0.60,P ＜ 0.01 ).　Conclusions　VM exists in the prostate cancer as an independent structure,and it is more common in the high-grade cancer.The progression-free survival of VM positive patients could be worse than the negative.MMP-2 and VM could be the indicators of poor prognosis.

Objective To evaluate effectiveness of the applying pelvic double-slice retractor in the division of bladder and prostate pedicles in male patients with previous surgery history during radical cystectomy (RC) and anterograde radical prostatectomy (ARP). Methods The pelvic double-slice retractor was used to expose the bladder and prostate pedicles in 43 RC (30 cases with BMI ＞ 28 kg/m2,16 cases had previous partial cystectomy) and 37 ARP ( all cases with BMI ＞ 28 kg/m2 ). Results The pelvic double-slice retractor provided excellent exposure for the division of bladder and prostate pedicles.The handling of bladder and prostate pedicles became easy and safe without unnecessary bleeding and injury to the rectum.The median operating time to control the pedicles during RC and ARP were 12 min and 7 min,and the average blood loss were 30 ml and 20 ml,respectively. Conclusion The use of pelvic double-slice retractor for the exposure of the bladder and prostate pedicles is simple and effective in male patients with complicated pelvic anatomy during RC and ARP.

Objectiye To study the levels of cartilage oligomeric matrixprotein (COMP) and matrix metalloproteinase-3 (MMP-3) in the serum fluid of osteoarthritic rabbit models and their relationships with the severity of pathological changes, so as to investigate their correlation with osteoarthritis(OA). Methods The osteoarthritic animal models were get from immobilizing the right knees of 18 rabbits in full extension using plaster cast. Knee joint pathological changes of 2,6 weeks were examined for pathological severity of OA; ELISA sandwich method was used to measure the levels of COMP and MMP-3 in serum before and after modeling( at 2, 6 weeks respectively); X ray of model keens was also obtained in different period.Correlation analysis was performed to demonstrate the relationship between the levels of COMP, MMP-3 in the serum and the pathological severity of OA. Results ( 1 ) Morphological observations: immobilizing the right knees of rabbits in full extension using plaster cast was a reliable methed for osteoarthritic animal models and the typical histopathologic character was seen; the severity of osteoarthritisgradually increased with time extended. (2) The levels of COMP[(3.64 ±0. 18)μg/L], MMP-3 [(1.99 ±0. 81 ) μg/L]in the serum of 2 weeks osteoarthritic animal models were higher than those before immobilizing with plaster cast [COMP(3.35 ±0. 20) μg/L,MMP-3( 1.61 ±0. 71 ) μg/L]. The levels of COMP[(3.96 ±0. 44) μg/L],MMP-3[(3.44 ±0. 91) μg/L] of 6 weeks were much higher,with a significant difference(P ＜0.05). The levels of COMP, MMP-3 in serum had a linear correlation with the pathological severity of OA (r ＞0. 710,and P ＜ 0. 05 ). Conclusion The levels of COMP and MMP-3 in serum can help to predict and evaluate the progression of OA.

Objective To evaluate the plan quality of volumetric modulated arc therapy (VMAT) in single brain metastasis compared with the stereotactic arc therapy (S_ARC).Methods 31 patients were replanned using VMAT and S_ARC technique.Prescription dose is 40 Gy delivered in 4 fractions covering at least 95％ of the target volume while keeping minimum doses to the volume of normal brain tissue.The plans were assessed and compared using the conformity indexes (CI),gradient indexes (GI),the mean dose of normal brain tissue,the volumes of normal brain tissue receiving 4 Gy doses,the number of monitor unit and treatment times.A paired t test or non-parametric Wilcoxon signed rank test was performed to analyze the difference between these two plans.Results VMAT plans increased dose conformity,but not dose gradient,compared with S_ARC plans.The median dose conformity index values were 0.815,0.818,and 0.779 (P =0.000,0.000),and the median dose gradient score index values were 5.865,5.706,and 3.133(P =0.000,0.000,0.000),in single arc,double arc VMAT plans and S_ARC plans,respectively.The mean dose of normal brain tissue was higher in VMAT plans.And the volume of the normal brain tissue receiving doses of 4 Gy in VMAT plans was significantly larger than the volume in S_ARC plans.The VMAT plans got higher MU number (P =0.000,0.000).And the mean treatment times were (2.7 ± 0.1) min,(2.8 ± 0.1) min,and (7.6 ± 0.2) min in single arc,double arc VMAT plans and S_ ARC plans,respectively (P =0.000,0.000).Conclusions The dosimetry of VMAT plan can meet the requirements of clinical,and is recommended in the treatment of big volume single brain metastasis or single brain metastasis in cerebellum.

Objective To evaluate the effects of four types of variance reduction techniques ( ring counter grid, high electron cutoff energy, termination of electron tracking in some structures, and emission direction?biased sampling of source) on the efficiency and accuracy of Monte Carlo simulation for the single source channel of the Leksell Gamma Knife. Methods The single source channel of the Leksell Gamma Knife was modeled using Monte Carlo software MCNP . Four types of variance reduction techniques were used to simulate the dose distribution in the water?like phantom. The computation efficiency and simulation result were compared between the four techniques. Results All techniques substantially improved the computation efficiency and had little effect on the accuracy of the simulation ( relative error less than 2. 5%) . However, if the electron cutoff energy was above 50 keV, the simulation became quite inaccurate due to neglect of the scattering of high?energy electrons and their dosimetric contribution to the penumbra. When the scattering of high?energy electrons and their dosimetric contribution to the penumbra were ignored, the dose to the Profile platform was overestimated and the dose to the penumbra was underestimated. Conclusions Rational use of variance reduction techniques can substantially improve the efficiency of Monte Carlo simulation for the single source channel of the Leksell Gamma Knife. However, the impact of variance reduction techniques on the accuracy of the simulation should be carefully evaluated.

Objective To develop whole breast irradiation with volumetric-modulated arc therapy (VMAT)-based hybrid intensity-modulated radiotherapy (IMRT) after breast conserving surgery for breast cancer,and to evaluate its value in clinical application.Methods Ten patients with breast cancer undergoing breast conserving surgery were enrolled.Two radiotherapy plans were designed based on hybrid fixed-beam IMRT/IMRT technique and hybrid VMAT/IMRT technique,respectively.One group received whole breast irradiation with a prescribed dose of 50 Gy in 25 fractions.The other group received whole breast irradiation with a prescribed dose of 50 Gy in 25 fractions,as well as simultaneous integrated boost to the tumor bed with 60 Gy in 25 fractions.The dosimetric parameters and delivery efficiency were compared between the two plans using paired t test.Results For patients treated with whole breast irradiation alone,there were no significant differences in conformity index and homogeneity index of target volume between the two plans (P=0.866,0.056);however,compared with the hybrid fixed-beam IMRT/IMRT technique,the hybrid VMAT/IMRT technique significantly increased the doses to organs at risk (OARs) and the number of monitor units (MUs) in the intensity-modulated field (P=0.000-0.050,P=0.002).For patients treated with whole breast irradiation with a simultaneous integrated boost to the tumor bed;however,the hybrid VMAT/IMRT technique significantly reduced the doses to the lung and spinal cord,number of MUs in intensity-modulated field,and delivery time compared with the hybrid fixed-beam IMRT/IMRT technique (P=0.004,0.001,0.000,0.000).Conclusions For patients treated with whole breast irradiation with a simultaneous integrated boost to the tumor bed,the hybrid VMAT/IMRT technique is highly promising for clinical application due to better OAR sparing and higher delivery efficiency.

Objective To evaluate the contribution of puboprostatic ligament-sparing technique in urinary continence after radical retropubic prostatectomy (RRP). Methods A total of 74 men with clinically localized prostate cancer underwent RRP. Of whom, 50 patients were performed pubo-prostatic ligament-sparing technique(group A), while 24 patients were not(group B). Patients were evaluated by independent observer questionnaire to determine their urinary continence status. Results Mean patient age [(61.3±2.4) vs (60.8±2.1)years], serum prostate-specific antigen (PSA) values [14.3±1.2)ng/ml vs (14.7±1.3) ng/ml], operative time [(110.5±10.4)min vs (109.7±10.6) mini, estimated blood loss [(250.5±23.4) ml vs (253.4±22.3) ml], and positive surgical margin rate (6% vs 8%) were not significantly different between group A and B(P>0.05). The urinary con-tinence rate with the puboprostatic ligament-sparing technique at 1-year follow-up was significantly higher than that of the control group (P<0.05). Concision The puboprostatic ligament-sparing technique significantly enhances post-operative urinary continence after RRP.